Light-sensitive silver halide supersensitized photographic material

ABSTRACT

A light-sensitive silver halide photographic material which contains at least one layer of silver halide emulsion including a combination of at least one benzimidazolo-carbocyanine dye represented by the general formula   -(CH2)2.O(CH2)2OH; R3 and R4 are individually a C1 to C4-alkyl, hydroxyalkyl, or sulfoalkyl group; Y1 and Y2 are individually a C1 to C4-alkyl group, ethoxyethyl group or an aryl group; X is a negative group; and n is 1 or 2; and at least one benzoxazolocarbocyanine dye represented by the general formula   WHEREIN R5 and R6 are individually a C1 to C4-alkyl or sulfoalkyl group; R7 is a C1 to C4-alkyl group; X is a negative group; and n is 1 or 2.

United States Patent Sato et al.

[ 51 May 16, 1972 [54] LIGHT-SENSITIVE SILVER HALIDE SUPERSENSITIZED PHOTOGRAPHIC MATERIAL [72] Inventors: Shui Sato, Tokyo; Eiichi Sakamoto, Hanno; Shizuo Saito, Tokyo; Kaiichiro Sakazume, Tokyo; Tokuzo Kaneko, Tokyo, all of Japan [73] Assignee: Konishiroku Photo Industry Co., Ltd.,

Tokyo, Japan [22] Filed: Apr. 15, 1970 [21] Appl. No.: 28,711

[30] Foreign Application Priority Data Apr. 19, 1969 Japan ..44/30086 [52] U.S. CI ..96/124, 96/137, 96/139 [51] Int. Cl ..G03c 1/14 [58] Field ofSearch ..96/123, 124

[56] References Cited UNITED STATES PATENTS 3,397,060 8/1968 Schwan et a1 ..96/124 Primary Examiner-J. Travis Brown Attorney-Waters, Roditi, Schwartz & Nissen [5 7] ABSTRACT A light-sensitive silver halide photographic material which contains at least one layer of silver halide emulsion including a combination of at least one benzimidazolo-carbocyanine dye represented by the general formula (CH O(CH OH; R and R are individually a C, to C -alkyl hydroxyalkyl, or sulfoalky group; Y and Y: are individually a C1 to C4-alkyl group, ethoxyethyl group or an aryl group; X- is a negative group; and n is l or 2: and at least one benzoxazolo-carbocyanine dye represented by the general formula wherein R5 and Rs are individually a C to C -alkyl or sulfoalkyl group; R is a C to Cralkyl group; X- is a negative group; and n is 1 or 2.

3 Claims, 3 Drawing Figures PATENTEDMAY 16 I912 v 3, 663. 21 0 Fig.1

g 400 500 600 700 Wavelengt h (mp) Fig. 2

g g 400 -500 e00 700 m- Wavelength(m u) Fig.3 1

E 400 500 600 700 Wavelength(m .1)

LIGHT-SENSITIVE SILVER HALIDE SUPERSENSITIZED PHOTOGRAPHIC MATERIAL This invention relates to a light-sensitive silver halide photographic material containing 2 or more sensitizing dyes in combination. More particularly, the invention is concerned with a lightsensitive silver halide photographic material containing at least one layer of a silver halide emulsion which has been highly sensitized by the combination of a certain kind of benzimindazolo-carbocyanine and a certain kind of benzoxazolo-carbocyanine.

The intrinsic light-sensitive wavelength region of a silver halide emulsion is ordinarily limited to a short wavelength region of ultraviolet light or blue light. It is well known that as a means for the spectral sensitization of such silver halide emulsion, the use of a certain kind of cyanine sensitizing dye is extremely effective.

It is also well known that when a silver halide emulsion is incorporated with a certain kind of sensitizing dye or organic compound as a second sensitizer in combination with the said sensitizing dye, the emulsion is enhanced in sensitivity to more than that recognized to be the sum of the effects of the individual compounds. Such enhancement in sensitivity is called as supersensitization, and many combinations of said sensitizing dyes have already been reported.

In applying such supersensitization to silver halide emul sions, it is desirable that the sensitizing dyes employed not only contribute to the increase in color sensitizing effects but also satisfy such conditions as mentioned below.

1. They should be proper in spectral sensitization region.

2. They should not have any adverse interactions with other photographic additives, and should have stable photographic properties even when the emulsions are allowed to stand or the resulting films or printing papers are stored.

3. They should not leave any color stain or fog on the films or papers after development.

Particularly, these conditions are important when the supersensitization process is applied to green light-sensitive emulsions for light-sensitive color photographic materials. That is, it is desirable that the sensitizing dyes have such spectral sensitization region as to attain the best color reproductivity when used in light-sensitive color photographic materials, and have a high speed green light-sensitivity.

Further, the sensitizing dyes are required to be such that they should not be lowered in speed by interaction with a magenta color image-forming component, i.e. a magenta coupler, which couples with an oxidation product of a color developer using p-phenylenediamine or the like, to give a color image.

However, according to the prior art processes for the combination of sensitizing dyes, there have not been obtained any combinations of sensitizing dyes which can satisfy the abovementioned conditions, particularly when used in light-sensitive color photographic materials.

- An object of the present invention is to provide a light-sensitive silver halide photographic material supersensitized by use of sensitizing dyes capable of satisfying all the above-mentioned conditions.

Another object is to provide a best green light-sensitive color photographic material containing sensitizing dyes, which can show a sensitization maximum at the wavelength region intermediate between the spectral sensitization maxima of individual sensitizing dyes.

As the result of extensive studies, we have found that when a certain kind of benzimidazolo-carbocyanine is used in combination with a certain kind of benzoxazolo-carbocyanine, not only a marked increase in color sensitization efficiency can be attained but also all the above-mentioned conditions are satisfied.

The supersensitizing dyes employed in the present invention are represented by the following formulas (l) and (II):

General Formula (I) R1 R2 i =0 H-CH=CH YiOOC wherein R, and R, are individually a C, to C,-alkyl or substituted alkyl group; R and R are individually a C, to C alkyl, hydroxyalkyl or sulfoalkyl group, or a derivative thereof; Y, and Y; are individually a C, to C -alkyl, a substituted alkyl, aryl or substituted aryl group; X' is a negative group (anion); and n is l or 2.

General Formula (II):

Typical examples of the dye represented by the formuld ll) are as follows:

I (C H2) 2303B $11918 0 However, sensitizing dyes usable in the present invention are not limited only to those mentioned above.

The combination according to the present invention-which comprises at least one of the sensitizing dyes of the aforesaid formula (I) and at least one of the sensitizing dyes of the formula (II) has excellent characteristics as mentioned previously and can impart ideal green-light sensitivity to silver halide emulsions. Accordingly, the combination of the present invention is desirably applied to green lightsensitive emulsions for internal color photographic materials which contain a magenta dye-forming coupler, or to orthomatic type emulsions for light-sensitive black-white photographic materials.

The location of spectral sensitization maximum of the silver halide photographic emulsion in accordance with the present invention may be varied by varying the kinds and proportions of the sensitizing dyes represented by the aforesaid formulas. These sensitizing dyes are dissolved in a water-miscible organic solvent such as methanol or ethanol and then the resulting solution is added to a silver halide emulsion. Alternatively, the sensitizing dyes are formed into organic solvent solutions, which are then added either singly or in admixture to a silver halide emulsion. Further, the addition of the sensitizing dyes to a photographic emulsion is most preferably made after completion of the second ripening, though the addition may sometimes be made at any stage'during the preparation of said emulsion. The amounts of the sensitizing dyes to be added vary depending on the kind of the silver halide emulsion. Ordinarily, however, the amounts thereof per kg. of the silver halide emulsion are such that the amountof the benzimidazolocarbocyanine dye of the formula (I) is l mg. to 200 mg., while the amount of the benzoxazolo-carbocyanine dye of the formula (ll) is 2 mg. to 400 mg., and the ratio ofthe dye (l) to the dye (ll) is preferably in the range of 4:1 to 1:20. However, the amounts thereof are not always limited to those mentioned above but may be varied as occasion demands.

The silver halide emulsion employed in the present invention may be any of silver iodobromide, silver bromide, silver chloride, silver chlorobromide and silver chloroiodide emulsions. These emulsions may have been subjected to chemical sensitization using noble metal sensitizers, sulfur sensitizers, reductive sensitizers or polyalkylene oxide derivatives. Further, they may be incorporated according to ordinary procedure with such additives as stabilizers, surface active agents, hardeners, etc.

When the color sensitizing process of the present invention is carried out in the presence of other carbocyanine or merocyanine dyes, high sensitivities (high photographic speed) can be provided so as to be suitable for application purposes, so that the color sensitization of light-sensitive photographic materials prepared by use of various silver halides can be easi- EXAMPLE 1 A silver iodobromide emulsion containing 3 mole of silver iodide which had been treated with a gelatine coagulant was subjected to second ripening according to the gold and sulfur sensitization process to prepare a light-sensitive photographic emulsion for high speed negative.

The thus prepared emulsion was divided into several portions, and each portion was incorporated with a methanol solution or methanol solutions of such two sensitizing dyes as shown in Table 1. Each of the thus treated emulsions was stirred at about 40 C. for 20 minutes to stabilize the color sensitization thereof and then coated on a film base, followed by drying to obtain an orthomatic type photographic material. The samples prepared in the above manner were subjected to KS-l type Sensitometer (manufactured by Konishiroku Photo Industrial Co.), exposed to a 160 lux day light lamp ,400 K.) through a green filter having a transmission maximum at 525 mu, and then developed at 20 C. for 5 minutes with a developer of the following composition:

Developer: Metol (N-methyl-p-aminophenol sulfate 3 g. Anhydrous sodium sulfite 50 g. Hydroquinone 6 g. Sodium carbonate (monohydrate) 29.5 g. Potassium bromide l g. Water to make 2 liters The results are shown in Table l, in which the relative speed is a value attained by regarding as 100 the green light-sensitivity of the sample incorporated with the dye of exemplrfication (2) alone.

TABLE 1 Sensitlvlty Relamaxi- Sam 1e Amount of sensitizing dye added Live mum num er (mg/kg. emulsion) speed Fog (Ill z) 1 Dye of exemplifleation (2) (20 mg.) 65 0.08 2 Dye of exemplification (2) (60 mg.) 100 0.05 580 Dye of exemplificatlon (2) (20 mg)... 8 plus 185 O. 06 570 dye of exemplification (17) mg.) Dye of cxemplification (2) (30 mg)... 4 plus 180 0.05

dye ol exemplilication (17) (30 mg)... 5 Dye of exemplillcation (4) (60 mg)... 110 0. 04 580 Dye ol cxomplification (4) (20 mg)... 6 plus 200 0.07 570 dye of oxemplilication (17) (40 mg.) Dye of exemplification (4) (30 mg.). 7 plus 195 0. 06

dye of exemplillcation (17) (30 mg). 8 Dye of exempllfication (7) (60 mg.) 85 0. 05 680 Dye ol' exempliflcation (7) (20 mg.) 9 plus 190 0.08 570 dye of exemplification (18) (40 mg). Dye of exemplification (7) (30 mg.). 10 plus 175 0. 07

dye of exemplification (18) (30 mg.) 11 Dye of exemplllicatlon (17) (60 mg)... 115 0. 09 650 12 Dye of exemplification (18) (60 mg)..- 110 0.10 550 As is clear from Table l, the samples (3), (4), (6), (7), (9) and (10) according to the present invention have excellent green light-sensitivities less in fog as compared with the sampics (i), (2), (5), (8) and (11) in which the individual dyes have been incorporated singly. The excellence of the samples in accordance with the present invention is further explained with reference to the accompanying drawings. FIGS. 1, 2 and 3 show, respectively, the spectral sensitivity curves of the sample (5), the sample (ll) and the sample (6) according to the present invention. From these drawings, it is recognized that the sample in accordance with the present invention has an excellent sensitization maximum which cannot be attained in the case where the sensitizing dye is used singly, and, from Table l and from the drawing, it is understood that the sample according to the present invention has excellent photographic properties.

EXAMPLE 2 A silver iodobromide emulsion for high speed negative which had been adjusted to the optimum speed according to the gold and sulfur sensitization process was divided into portions of each 1 kg. in amount, and each portion was incorporated with a 0.1 percent methanol solution of each of the sensitizing dyes shown in Table 2. The thus treated emulsion was stirred at 40 C. for about 20 minutes and then charged with 35 ml. of a 0.5 percent aqueous solution of 4-hydroxy-6- methyll ,3,3a,7-tetrazaindene as a stabilizer.

Separately, l-( 2,4,6-trichlorophenyl )-3-[ 3-( 2,4-di-tertamylphenoxyacetamide)benzamidehS-S-pyrazolone as a magenta coupler was dissolved at an elevated temperature in a mixture comprising di-n-butyl phthalate and ethyl acetate, and the resulting solution was dispersed in a gelatine solution by use of sodium alkylbenzenesulfonate. Thereafter, a given amount of the resulting dispersion was added to the aforesaid emulsion, and then the mixture was adjusted to pH 6.8 to prepare a green light-sensitive color photographic emulsion. For comparison, an emulsion was prepared in the same manner as above, except that the dye of exemplification (l) was used singly. I

Each of the thus obtained emulsions was immediately coated on a film base, followed by drying to prepare an immediately-coated sample. On the other hand, each of the emulsions was allowed to stand at 40 C. for 3 hours and then emulsions a combination of methanol solutions of the sensitizing dyes as shown in Table 3, adding in the same manner as in Example 2 l-(2,4,6-trichlorophenyl)-3-[3-(2,4-di-tert.- amylphenoxyacetamide)benzamide] as a magenta coupler,

coated on a film base, followed by drying to prepare a later- 5 and then adjusting the resulting mixture to pH 6.8. coated sample. For comparison, an emulsion was prepared in the same In r r I test the r lh y Of these 5311113165, the manner as above, except that the following sensitizing dyes mediately-coated samples were individually stored at 55 C. disclosed in U.S. Pat. No. 2,688,545 were used in combinafor 3 days, and at 50 C. and humidity of 80 percent for 3 days, tion: to prepare stored samples (a) and (b), respectively. 10

- CZILS C 11 The thus prepared samples were exposed in the same manner as in Example 1 and then subjected to color development at 21 C. for minutes with a color developer of the fol- C1 C1 lowing composition: i

C1 Cl N-Ethyl-N-Bmethanesulfonamidoethyl- N 3-methylaminoaniline sulfate 2.5 g. (E2115 C2H5 Anhydrous sodium sulfite 2.0 g. Benzyl alcohol 3.8 ml. (B) O 0 Sodium hexamethaphosphate 2.0 g. Sodium carbonate (monohydrate) 50.0 g.

. CII C CH- Potassium bromide 1.0 g. Caustic soda 0.6 g. C 11 Water to make 1 liter +111 SCN- C2115 Cells After the development, the samples were subjected to ordinary bleaching, fixing and water-washing and then measured The thus prepared emulsion was coated on a film base so in green light-sensitivity and fog to obtain the results as set that the thickness of the resulting film was 6a. The thus forth in Table 2, provided that the relative speed shown in the formed film was further coated with an yellow filter layer comtable is a value attained by regarding as 100 the green lightprising colloidal silver, and then coated to a thickness of 5p. sensitivity of the sample prepared by using the dye of exemwith an emulsion prepared by dispersing in the same manner Phficatlon (1) yas above 2-dodecyloxybenzoylacetanilide as an yellow coupler TABLE 2 Immediately- Later-coated Stored sample Stored sample coated sample sample (a) Sample Amount of sensitizing dye added (mg/kg. Relative Relative Relative Relative Number emulsion) speed Fog speed Fog speed Fog speed Fog 13 Dye oiexemplillcation (1) (6Oiiig.) ........v 100 0.03 98 0.04 95 0.03 100 0.03

Dye of exemplilication (1) (20 mg.) 14 plus 200 0. 04 205 0.05 200 0.05 195 0.04

Dye oi exeinplilication (19) iiig.).. Dye of exemplitieatioii (1) (40 mg.) 15 plus 100 0.03 185 0.04 185 0.04 190 0,04

Dye of exeniplilication (19) (20 mg.) Dye 01' exemplifieatioii (11) (20 mg.) 16 plus 185 0.04 190 0.04 185 0.04 180 0.04

Dye of exemplifieation (20) (40 mg.) Dye of exeinplilieation (11) (40 mg.) l7... plus 170 0.03 170 0.03 175 0.03 170 0.03

Dye of exerilplification (20) (20 mg.) 18 Dye of exemplification (10) (60 rng.) 120 0.07 125 0.08 115 0.07 120 0.07 10 Dye of exemplifieation (20) (60 mg.) 100 0.08 105 0.08 100 0.00 05 0.08

As is clear from Table 2, the light-sensitive silver halide in asilveriodobromide negative emulsion sensitized according photographic materials according to the present invention are to the gold and sulfur sensitization process, and then adjusting high in green light-sensitivity even when used in the presence the resulting mixture to pH 6.8. of a magenta coupler, and are not fogged nor deteriorated in The multi-layer color photographic materials obtained in color sensitization even when allowed to stand or stored under the above were exposed the Same manner as a p 1, severe conditions. developed at 22 C. for l0 minutes with the aforesaid color EXAMPLE 3 developer, bleached and fixed according to ordinary I I procedures, and then subjected to sensitometry.

A hlgh Speed lodobfomlde i fi i The green light-sensitivities and residual color properties of photograp 1c g i g g i l 2; 0 0 81 f the magenta color layers thus formed are shown in Table 3, in Iodide was spctrany sensmze men 0 h which the relative speed is a value attained by regarding as of the em'ulslon of f i 'f f the green light sensitivity of the control. fopropylthiacarbocyanine as a red light-sensitive sensitizing y TABLE 3 Separately, 4-chloro-l-hydroxy-2-n-octylnaphthamide as a Residual cyan coupler was dissolved at an elevated temperature in a Sample Amount ofsensitiziug dye added Relative color mixture comprising di-n-octylnaphthamide and ethyl acetate, 65 number emulswn) Speed PWWTW and the resulting solution was dispersed in a gelatine solution 2 Dyils of exenipllfication (4) (20 mg.) r.. no 0 05 p us by use of sodium alkylbenzenesulfonate. of amplification (17) (40 mgJm A given amount of the thus obtained dispers on was added 21 DYIB of exemplifieation (4) (20 mg.) 5 0 04 to the aforesaid emulsion, and then the emulsion was adjusted 7o g g amplification g) to pH 6.8 and coated on a film base so that the thickness of the Dye of exemplification (3) (20 mg.)

. h f d H l 22 plus 110 0.04 resulting film was 5a. Further, the t us orme i m was t in Dye f amplification (3) (20 mgjnn coated with gelatine and then coated with a green light-sensi- 23 g g cxempllficatm" (3) (20 0 n5 tive color photographic emulsion prepared by dividing the Dy0 ofcmmpjmcauon (19) (40 mm H same high speed silver iodobromide emulsion as in Example 1 24 Control y mg.) p on l into portion of 1 kg. in amount, adding to each of the divided dye (ll) (40 mph).

Table 3 shows the fact that the combinations of the dyes according to the present invention are more excellent in speed of magenta layer as green light-sensitivity and lower in residual color property than the combination of the dyes used as controls, and give excellent light-sensitive multi-layer color photographic materials.

EXAMPLE 4 A reversal color photographic silver iodobromide emulsion containing 3 mol of silver iodide which had been treated with a gelatine coagulant was subjected to second ripening according to gold and sulfur sensitization. After completion of the ripening, the emulsion was divided into several portions of each 1 kg. in amount. To each portion of the divided emulsions were added in combination methanol solutions of the sensitizing dyes shown in Table 4. Each of the emulsions was stirred at 40 C. for 20 minutes to thoroughly stabilize the color sensitization thereof, and then an optimum amount of a stabilizer was added thereto. Into this emulsion was dispersed according to an ordinary procedure l-(3-carboxyphenyl)-3- (4-stearoylaminophenyl)-5-pyrazolone as a magenta coupler, and the resulting dispersion was adjusted to pH 6.8 to prepare a green light-sensitive reversal color photographic emulsion. Each of the thus prepared emulsions was coated on a film base, followed by drying to obtain a sample, which was then exposed in the same manner as in Example 1 and then developed at 20 C. for minutes with a first developer ofthe following composition:

First developer:

Metol (N-methyl-p-aminophenol sulfate) Anhydrous sodium sulfite Hydroquinone Sodium carbonate (monohydrate) Potassium bromide Potassium thiocyanate Water to make u. ---mouioiu MOGQ FOQ P iter.

After ordinary stopping, film-hardening and water-washing treatments, the developed sample was subjected to second exposure by use of a white light, and then developed at C. for 12 minutes with a developer of the following composition:

Second developer:

N,N-Diethyl-p-phenylenediamine sulfate 5 g. Anhydrous sodium sulfite 2 g. Sodium carbonate (monohydrate 32 g. Potassium bromide l g. Water to make 1 liter.

TABLE 4 Fog (m Sample Amount of sensitizing dye added Relative sidual number (mg/kg. emulsion) speed color) Dye of exemplification (3) (30 mg.)

25 plus 0.03

Dye of cxcmpliiication (17) (40 mg.) Dye of exomplification (4) (30 mg.)

26 plus 0.04

Dye of oxcmpliiication (i7) (40 NHL)... Dye of cxvmpliiication (6) (30 mg.)

.27 plus 105 0.03

Dye of t-xvmplilication (i7) (40 man). l)yo 0ivxumpliiicaiion (i3) (30 mg). I

28 plus llll 0.03

Dyv. ofoxomplilicntion UT) 40 mg.)

29 Control dye (A) (30 mg.) plus control 100 0.04

dye (B) (40 mg).

As is clear from Table 4, the light-sensitive reversal color photographic materials according to the present invention have excellent photographic properties as compared with the control sample.

What we claim is:

l. A light-sensitive silver halide photographic material characterized by containing at least one layer of a silver halide emulsion incorporated with a combination of at least one benzimidazolo-carbocyanine dye represented by the general wherein R, and R are individually a C, to C,-alkyl or a group wherein R,and R are individually a C, to C.,-alkyl or substituted alkyl group; R and R, are individually a C, to C.,-alkyl, hydroxyalkyl, or sulfoalkyl group, or a derivative thereof; Y, and Y, are individually a C,'to C -alkyl, substituted alkyl, aryl or substituted aryl group; X is a negative group; and n is l or 2;

at least one benzoxazolo-carbocyanine dye represented by the general formula (XI?) n-l wherein R and R are individually a C, to C -alkyl or sulfoalkyl group; R, is a C, to C.,-alkyl group; X is a negative group; and, n is l or 2.

2. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said silver halide emulsion is an orthomatic type emulsion.

3. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said silver halide emulsion has been incorporated with a magenta coupler. 

2. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said silver halide emulsion is an orthomatic type emulsion.
 3. A light-sensitive silver halide photographic material as claimed in claim 1, wherein said silver halide emulsion has been incorporated with a magenta coupler. 